Tuesday, Oct. 15, 2013 | 1:21 p.m.
GMG company officials said the disruption lasted from about 6:20 until 10 a.m.
Officials said the sites were targeted in an attack known as “distributed denial of services,” or DDoS, in which networks of computers known as “botnets” overwhelm servers that maintain sites.
Botnets are controlled by an attacker and operated remotely, typically without the knowledge of their owners, and can be made up of hundreds of thousands of computers worldwide.
The networks can be given commands to send information to a targeted site, flooding it with data and blocking legitimate users from gaining access to it.
DDoS attacks occur frequently through the use of relatively inexpensive software and rented botnet time. Motives range from mischief to criminal intent, including extortion.
This month, a federal grand jury in Virginia indicted 13 people for allegedly launching or attempting to launch cyberattacks against government entities, trade associations, individuals, law firms and financial institutions.
Officials said such organizations as Visa, MasterCard, Bank of America, the Motion Picture Association of America and the United States Copyright Office were targeted.
In other high-profile news on the subject, the New York Times website was taken offline for several hours during August in what was initially termed a “malicious external attack.”
GMG officials said the company was taking action to prevent future disruptions from DDoS attacks. Citing security reasons, officials declined to divulge details about the prevention efforts.